Create multiple frames with fits file

Hi,

I am trying to create a single fits file with multiple frames. I have attached the Coding. At the end, i need to get a single fits file with 26 frames, but my code is producing just a single frame. Can someone please help? TIA

[Walter Roberson]

In your previous question https://www.mathworks.com/matlabcentral/answers/456817-select-multiple-frames-from-a-single-fits-file (which is waiting for a response from you), you were not dealing with multiple frames: you were dealing with a multidimensional array. Are you now trying to create multiple frames, or are you trying to create a multidimensional array?

Your previous question dealt with image frames, but the current one deals with primary data. Which one are you wanting to use?

[Kiruthiga Sekar]

That was a different code and this is a different code. I need to select 20 frames from 2700 frames of a single fits file, and create another fits file with the 20 frames.

[Walter Roberson]

That code looks like it should work. Did you try the second example at https://www.mathworks.com/help/matlab/ref/fitswrite.html to see whether it generally works?

What shows up when you fitsdisp() the output file?

I do notice that fitswrite() seems to create the first array as primary instead of Image, so the maximum index using fitsread(filename, 'image', index) format is one less than expected.

[Kiruthiga Sekar]

fitsdisp() output:

HDU : 1(Primary HDU)

%some values%

HDU : 2

%some values%

:

:

:

HDU: 76

%some values%

[Walter Roberson]

Do HDU 2 to 76 all show up with XTENSION = 'IMAGE '

If so then 2 through 76 are all frames that can be indexed with fitsread(filename, 'image', index) by using the HDU number minus one as the index (so index 1 to 75 in this case.). The first frame would have to be read with fitsread(filename, 'primary', 1) it appears.

[Kiruthiga Sekar]

I ran it now it is displaying upto HDU : 184

Yes . it is showing XTENSION = 'IMAGE' for 2 to 184 now!

[Walter Roberson]

Remember you are not deleting the file before you append to it, so the more you run the code, the longer the file is going to get.

[Kiruthiga Sekar]

Sorry.. I cant get what you are asking me to do.

[Walter Roberson]

if exist('new.fits', 'file'); delete('new.fits'); end

before you start writing data to it.